Skip to main content

Standard Shipping Box Sizes for USPS, UPS, & FedEx

Even considering only the three major mail carriers, eCommerce businesses must confront hundreds of options when it comes to box sizes. USPS, UPS, and FedEx cumulatively offer more box sizes than any business could ever need. This may give business owners lots to choose from, but it can also be overwhelming.

To make informed decisions that save money on fulfillment costs, businesses need to know what their options are. To help you choose the right carrier and box size to save on shipping charges, in this article we discuss:

  • How box size relates to shipping costs
  • Box size options for the major mail carriers
  • How a 3PL can help with fulfillment costs

Box Size and Shipping Calculations

Shipping carriers charge your business based on the weight and size of the boxes they ship for you. Each carrier and each size bracket within them has its own maximum weight limit used to determine the price you will be charged

However, it’s important to note that there are two types of weight that carriers use to calculate your shipping charges. The first is your product’s actual weight in pounds. This number represents the most that many businesses worry about when it comes to reducing shipping costs. However, carriers may not use the actual weight to calculate shipping charges if the product’s DIM weight is larger.

DIM weight uses the package’s dimensions in its calculations of your final shipping charges. The carrier chooses whichever weight is the higher of the two to bill your business.

The reason DIM weight is important for mail carriers is that businesses might sell products that are light but large such as curtains, bathroom rugs, or large display items that cannot be reduced into smaller packaging. Since the carrier’s delivery trucks have to make more trips with items that are physically larger, box size can directly factor into how much they charge you.

Box Size Options from the Major Carriers

Each major carrier has numerous boxes to choose from. We break down the rates of each carrier’s major boxes to help you decide which to use for what kind of delivery.


USPS offers many shipping solutions. However, their flat-rate boxes are the most advantageous for eCommerce companies hoping to ship many small items. The post office offers free shipping supplies and even priority mail deliveries that can take advantage of the post office’s fulfillment system to deliver local items more cheaply than other major carriers.

Here are some options for USPS’s boxes, both priority mail and flat rate:

Box Type Price Maximum weight Maximum dimensions
Priority Mail Express flat rate envelope $27.10 Post Office

$23.50 Commercial Base

70 lbs. 108”
Priority Mail flat rate $7.95 Post Office

$7.41 Commercial Base

70 lbs. 108”
Priority Mail Regional Rate Boxes $8.08 Post Office 70 lbs. 108”
First-Class Mail $0.58 (letters)

$0.88 (oversized letters)

$1.16 (large envelopes)

$4.30 (small packages)

3.5 oz (letters)

13oz (parcels)

First-Class Package Service $3.31 Commercial

$4.30 Retail

70 lbs. 22”x18” x 15”
Flat Rate Envelope $8.70 70 lbs. 12 ½” x 9 ½”
Padded Flat Rate Envelope $9.30 70 lbs. 12 ½” x 9 ½”
Small Flat Rate Box $9.20 70 lbs. 8 11⁄16″ x 5 7⁄16″ x 1 3⁄4″
Medium Flat Rate Box $16.25 70 lbs. 11 1⁄4″ x 8 3⁄4″ x 6″

(top loading)

14″ x 12″ x 3 1⁄2″

(side loading)

Large Flat Rate Box $22.65 70 lbs. 12 1⁄4″ x 12 1⁄4″ x 6″


APO Large Box $21.15 70 lbs. 12 1⁄4″ x 12 1⁄4″ x 6″


USPS is most often used for their flat rate shipping services, which benefits businesses that sell many small, similarly sized items. Use the above chart to figure out if your most commonly sold merchandise qualifies for its more affordable rates.

USPS also offers boxes designed for specific item descriptions, such as these DVD boxes. They can be ordered in packs of 25 and are sized as 8 ¾” x 5 91/6” x 7/8”, which is big enough for one or two DVDs or CDs per box. These and many other shipping supplies can be shipped to your business for free. You must use USPS shipping services to take advantage of this offer, but for businesses that sell many DVDs, often in multiples to the same customers, these boxes can be a lifesaver for your profit margins.


UPS offers boxes that you can order from their store, many of which are also listed on the UPS website as free for businesses that need them. UPS express offers many size-based shipping boxes that businesses should be able to distinguish between to choose the right services for their needs.

Box Size Prices Maximum Weight Potential Uses
1-100 in3 (XS) $8.80 (Ground)

$14.65 (3-Day Select)

$17.70 (2nd-Day Air)

$25.75 (Next Day Air Saver)

70 lbs. Shirts, mugs, glasses, phone accessories, writing implements, small toys
101-250 in3 (S) $11.50 (Ground)

$17.70 (3-Day Select)

$21.10 (2nd-Day Air)

32.75 (Next Day Air Saver)

70 lbs. Books, packs of paper, notebooks
251-650 in3 (M) $13.90 (Ground)

$25.20 (3-Day Select)

$27.00 (2nd-Day Air)

$36.80 (Next Day Air Saver)

70 lbs. Binders, shoes, hats
651-1,050 in3 (L) $18.40 (Ground)

$33.75 (3-Day Select)

$48.15 (2nd-Day Air)

$55.15 (Next Day Air Saver)

70 lbs. Football, small laptop, large books
1,051-1,728 (XL) $22.85 (Ground)

$42.40 (3-Day Select)

$62.40 (2nd Day Air)

$71.40 (Next Day Air Saver)

70 lbs. Sports equipment, large laptops, kitchen appliances

UPS offers these fixed-price shipping boxes depending on the size you need and the delivery timeframe you require. Taking advantage of their shipping services requires knowing in advance which boxes are best for the kinds of items you ship.

In addition to boxes, UPS also offers tubes, which are necessary for mailing blueprints, drawings, or important documents. They have protective pouches that can display the inside to the recipient. Paks are corrugated boxes that allow shippers to cover the item tightly, which is ideal for items that are large, flat, and sturdy.

One notable difference between UPS and the other carriers is that as a federal organization, their prices can be used to ship your custom or DIY shipping boxes that fit within the parameters of their size and weight limits. With the other carriers, the boxes used in their system must be their branded products to maintain uniformity and encourage businesses to use them based on the offer for free supplies.


FedEx offers many box sizes for different kinds of merchandise. They are best used by stores that sell a lot of products of different dimensions, such as an electronics store that sells both replacement chargers and computer mice but also TVs and game systems.

Their standard box sizes come in flat rates that change depending on the distance the items need to ship. We listed the dimensions of the boxes to give you some idea of what you should be using them for:

Box Size Local Shipping Rate Regional Shipping Rate National Shipping Rate
FedEx Envelope

(9½” x 12½”)

$7.50 $8.00 $9.75
FedEx Pak

(10¼” x 12¾”, 12″ x 15½”)

$7.50 $8.00 $9.75
FedEx Small Box

(10 7⁄8″ x 1½” x 12 3⁄8″)

$8.50 $9.75 $10.75
FedEx Medium Box

(11 ½” x 2 3/8” x 13 ¼”)  

$10.50 $12.25 $14.00
FedEx Large Box

(12 3/8” x 3” x 17 ½”)

$15.75 $17.25 $18.75
FedEx Extra Large Box

(11 7/8” x 10 ¾” x 11”)

$24.75 $28.00 $39.25
FedEx Tube

(6” x 6” x 38”)

$24.75 $28.00 $39.25

In addition to these boxes, FedEx also offers boxes named after the item they were designed to contain, such as golf bag boxes, instrument boxes, and laptop boxes. FedEx offers many dozens of these options for stores with uniquely sized or shaped items and can be used to the advantage of eCommerce stores that sell a diverse array of items.

How a 3PL Can Help with Fulfillment Costs

3PL services can help with your fulfillment process by offering you their expertise in choosing box sizes for your business’s needs. Examples of third-party fulfillment services include:

  • Comparing options between carriers to give your business the most cost-effective choices available
  • Negotiating with carriers to get the most competitive DIM shipping rates
  • Consolidating products into as few boxes as possible while choosing the most cost-effective boxes for your business’s item types. 
  • Weight and size consolidation includes not only selecting the right box sizes but also choosing the most cost- and size-efficient fillers to save on your product weight.
  • Splitting orders between boxes to improve cost efficiency, which can radically impact how mail carriers calculate your products’ DIM weight.

A 3PL like eWorld Fulfillment can help eCommerce businesses satisfy their customers by negotiating lower shipping costs and using their expertise to pack your items most cheaply and efficiently. With hundreds of options out there for shipping boxes, the right third-party fulfillment company can help you navigate one of the most confusing, yet cost-saving processes your eCommerce enterprise will ever face.